The present invention relates to a method and to a device for automatic pneumatic charging of a plurality of receiving stations each provided with a preliminary storing bin, with a pulverized or granulated material.
In plant technology it is frequently required to charge substantially simultaneously a large number of receiving stations spaced apart from each other at certain intervals, with pulverized or granulated material. For example an aluminum producing plant which has a large number of premises for processing raw aluminum oxide, it is necessary due to the relatively low capacity of the furnaces to charge the latter in more or less regular time intervals. Such furnaces are arranged in the so-called furnace house in rows of 25 furnaces each and the total number of such furnaces may amount up to 150.
A prior art method of charging such furnaces is based on providing each furnace with a preliminary hopper acting as a buffer container and supplying aluminum oxide in each hopper by means of charging vehicles. Since each furnace consumes about 100 kg. of aluminum oxide per hour such prior art method necessitates a large number of attaining personal and moreover it is very noisy, causes air pollution in the entire plant and is prone to work accidents.
In another known solution of the beforementioned problem the granulated or pulverized material is transported mechanically by means of worm conveyors or pneumatically by means of pneumatic conveyors. Current pneumatic conveying systems for this purpose, however, are very costly due to the multitude of pipe branches, pipe switching points and material shutoff elements such as flaps or the like, and also the operation and maintenance of such complicated transportation systems becomes rather expensive because the conveyed material, such as alumin oxide is very abrasive and makes the transportation unreliable due to the wear in the conveying lines, resulting in frequent dead times and a considerable expenditures for the repair work and spare parts.